The present invention generally relates to a leak-proof reclosable package, such as a plastic bag, that includes a zipper closure arrangement. More specifically, the present invention relates to a zipper closure arrangement having reclosable profiles and a slider device having a full-length plow to open and close the profiles as the slider is moved along the length of the profiles.
Many packaging applications use reclosable containers to store various types of articles and materials. These packages may be used to store and ship food products, non-food consumer goods, medical supplies, waste materials, and various other types of articles. Reclosable packages are convenient in that they can be closed and resealed after the initial opening to preserve the enclosed contents. The need to locate a storage container for the unused portion of the product in the package is thus avoided. As such, providing products in a reclosable package appreciably enhances the marketability of these products.
Some types of reclosable packages are opened and closed using a slider device. The slider device typically includes a separator or plow-type structure in the middle or at one end that opens a zipper closure mechanism having male and female interlocking profiled elements or closure profiles when the slider device travels in a first direction along the zipper closure. The sidewalls of the slider device are inwardly tapered from one end to the opposite end so that the sidewalls engage the closure profiles and progressively move them into engagement to close the reclosable package when the slider device is moved along the zipper closure in a direction opposite to the first direction.
Reclosable packages that include a slider device to more easily open and close the profiles typically face problems in providing a liquid tight seal across the entire length of the zipper closure due to the fact that the slider includes a plow device used to separate the closure profiles as the slider is moved along the length of the zipper closure. Thus, a portion of the zipper closure beneath the plow remains open at all times. One way to solve this problem is to include a notch formed in the mating profiles above the interlocking elements to define a home position for the slider when the package is in a completely closed position. The notch formed in the profile typically receives the plow formed on the slider such that the profile can be closed on each side of the plow to create a continuous seal across the entire package. Typically, the plow of the slider device does not extend past the interlocking elements such that the notch does not create an opening between the interlocking elements formed on the closure profiles.
Although a notch formed in the mating profile on the closed end of the resealable package is known, problems can occur in utilizing such a notch with a full-length plow. For example, during the formation of the notch, portions of the resealable package near the location of the notch can be damaged which affects the performance of the package.
Therefore, it is an object of the present invention to provide an improved zipper closure mechanism and slider that creates a liquid tight seal across the entire length of the zipper closure. Further, it is an object of the present invention to provide a slider device for use on such a zipper closure mechanism that includes a one-piece, full-length plow for separating the mating closure profiles.
The present invention is directed to a reclosable, flexible package that includes a slider device and zipper closure that closes the mouth of the package. The slider device is movable along the zipper closure to engage and disengage a pair of closure profiles.
In accordance with the invention, the zipper closure includes a male closure profile and a female closure profile that engage each other to seal the zipper closure along the mouth of the product package. The slider device is positioned to move along the pair of closure profiles to engage and disengage the closure profiles as the slider device is moved.
The male closure profile includes a base wall having a first interlocking member extending therefrom. The female closure profile includes a second base wall including at least one second interlocking member extending from the base wall. The first and second interlocking members are constructed and arranged to selectively interlock to close the mouth of the flexible package.
The male closure profile includes a sealing protrusion that extends toward the female closure profile. In the preferred embodiment of the invention, the sealing protrusion is formed as part of the first base wall and is positioned between the first interlocking member and the open interior of the package, although other locations are contemplated as being within the scope of the present invention. The female closure profile includes a sealing recess that is sized to receive the sealing protrusion extending from the male closure profile. When the male and female closure profiles are interlocked, the sealing protrusion is received within the sealing recess to provide a fluid seal for the open package interior. In the preferred embodiment of the invention, the sealing recess formed on the female closure profile is positioned between the second interlocking member and the open package interior, although other locations are contemplated as being within the scope of the present invention.
The slider device includes a plow that depends from a top wall of the slider device. The plow extends toward the open package interior when the slider device is positioned along the zipper closure. The plow extends downward from the top wall and extends between the first interlocking member and the second interlocking member of the zipper closure. Thus, the slider device physically separates the first interlocking member and the second interlocking member as the slider device is moved along the zipper closure.
Preferably, the plow of the slider device is a one-piece member that has a pair of diverging sidewalls that separate the male closure profile and the female closure profile as the slider device is moved in a first direction.
The slider device includes an open interior that receives the male and female closure profile. Preferably, a pair of slider ribs are formed on the opposing sidewalls that define the open interior of the slider device. The slider ribs decrease in height from the first end of the slider device to a second end of the slider device. The increasing height of the slider ribs contact the male and female closure profiles to force the male and female closure profiles into an interlocking condition as the slider device moves in a second, opposite direction.
Both the male closure profile and the female closure profile include a spring member that contacts the inner surface of the top wall of the slider device. The spring members compensate for the size of the open interior of the slider device and aids in the installation of the slider device onto the zipper closure.
In accordance with the present invention, a notch or slit is formed in the zipper closure to define a home position for the slider device. The notch or slit formed in the zipper closure preferably extends through both the male and female closure profiles such that the plow formed on the slider device can be received in the notch or slit.
A first seal region is formed between the panels of the reclosable package beneath the notch formed in the zipper closure. The seal region provides a liquid tight seal beneath the notch formed in the zipper closure such that liquid is prevented from leaving the open interior of the package through the open closure around the plow or separator.